Alan Turing was a renowned scientist who cracked Germany’s Enigma code during the Second World War.

Experts believe his work shortened the conflict by two years.

Working at the top-secret Government Code and Cypher School at Bletchley Park, in Buckinghamshire - the forerunner of Britain’s spy centre GCHQ - Turing devised groundbreaking techniques to crack the wartime communications codes used by German military chiefs.

(Photo: PA)

But he courted controversy when he was convicted of gross indecency and sentenced to “chemical castration” in 1952.

He died two years later, aged 41, of cyanide poisoning, which an inquest determined was suicide although his family believed that it was accidental.

(Photo: PA)

After a long campaign to wipe the conviction from his record, the Queen granted Turing a posthumous pardon under the Royal Prerogative of Mercy.

The pardon finally clears the name of the man who has often been described as the “father of modern computing”.